控制性语言对提高技术规范文本机器翻译质量的实证研究

控制性语言可实现词汇及风格的标准化,保证信息内容前后的一致性,消除歧义,降低语言的复杂程度,质量控制具有客观的标准可以遵循.控制性语言在一定程度上降低了自然语言的复杂性,相应地可以提高翻译质量,因而引起了机器翻译研究人员的关注.以技术规范文献的英汉机器翻译为例,讨论控制性语言的生成规则,使用控制性语言的益处及其对提高机器翻译质量所起的作用.     

Integrated scheduling and inventory management of an oil products distribution system

The oil supply chain is facing new challenges due to emerging issues such as new alternative energy sources, oil sources scarcity, and price variability with high impact on demand and production and profit margins reduction. Additionally, the existence of large, complex and world wide spread businesses implies a complex system to be managed where distribution can be seen as one of the key areas that needs to be efficiently and effectively managed. Different types of distribution modes characterize the oil supply chain where the pipeline mode is one of the most complex to operate when having multiproduct characteristics. This paper addresses the planning of a generic oil derivatives transportation system characterized by a multiproduct pipeline that connects a single refinery to a storage tank farm. Two alternative mixed integer linear programming models (MILP) that aim to attain a set of planning objectives such as fulfilling costumers’ demands (which is mandatory) while minimizing the medium flow rate are developed. Additionally, final inventory levels are avoided to be excessively low. A real world scenario of a Portuguese company is used to validate and compare the two alternative MILP models developed in this paper.     

Production planning and control in automated manufacturing systems

Automated manufacturing systems (AMSs) have the potential for providing a high level of manufacturing performance. Owing to the high cost of capital investment, a high utilization level of AMSs with the help of suitable production planning and control (PPC) is feature of AMSs. Realizing the potential of PPC in AMSs, an attempt has been made to review the available techniques/methods for solving the problems of production planning, control and scheduling in AMSs. The need for further research on PPC of AMSs is brought to the fore along with future research directions.     

Optimum common cycle for scheduling a single-machine multiproduct system with a budgetary constraint

This paper deals with the single machine multi-product lot size scheduling problem, and has two objectives. The first objective is to minimize the maximum aggregate inventory for the common cycle (CC) scheduling policy. A simple and easy-to-apply rule has been developed which determines the optimal production sequence that achieves this objective. The second objective is to find an optimal common cycle for minimizing the average production and inventory costs per unit time, subject to a given budgetary constraint. A method has been presented that achieves this objective     

Shop floor characteristics influencing the use of advanced planning and scheduling systems

The purpose of this article is to investigate how the manufacturing process, the shop type and the data quality, i.e. the shop floor characteristics, influence the use of advanced planning and scheduling (APS) systems in production activity and control (PAC). The methodology implemented is a multiple case study at three case companies. Each company has different shop floor characteristics, but all use a scheduling module in an APS system, which supports production scheduling. A theoretical framework is developed suggesting how APS system are used in the PAC activities, and which major aspect to consider. The case analysis shows that the scheduling module in APS system, foremost supports sequencing and dispatching. In particular, the shop type is influenced by the decision of how often the APS runs and what freedom is given to the shop floor. The manufacturing process influences how the dispatch list is created. Contrary to the literature presuming that APS systems are most suitable in job shop processes, it is found that the manufacturing process is not a crucial factor when deciding whether APS systems are an appropriate investment. It is found that the level of data quality needed in the APS system depends to a large extent on how the dispatch list is used. For example, is the dispatch list used as a guideline, not a regulation, the need for accurate data in the module is reduced. This article extends the previous literature concerning APS systems by analysing how APS systems influence PAC as a whole and increase the understanding of the challenges of using APS systems in PAC.     

An integrated modelling approach for raw material management in a steel mill

An integrated modelling approach combining optimisation models with simulation is proposed for coordinated raw material management at steel works throughout the whole supply chain management process. The integrated model is composed of three components: ship scheduling, yard operation simulation and material blending models. The ship scheduling model determines which brands, how much and when they should be arrived, and the problem is modelled as mixed integer linear programming. The simulation model is used to simulate the whole processes from ships’ arrivals to the retrieval of the materials through the berthing and unloading the raw materials. Finally, the raw material blending model is developed for determining the brand and quantity of raw materials to be used. The proposed integrated modelling approach for raw material management has been successfully implemented and applied at steelwork to provide shipping schedules and predict future inventory levels at stock yards. By coordinating all the activities throughout the entire raw material supply chain management process, this article proposes an integrated approach to the problem and suggests a guideline by the appropriate simplification. The quantitative nature of the optimisation model and simulation facilitates an assessment of the risk factors in the supply chain, leading to an evaluation of a wide variety of scenarios and the development of multiple contingency plans. Further research is expected to supplement the ship scheduling models with heuristics for the idiosyncratic constraints of maritime transportation.     

混合核函数对支持向量机分类性能的改进

通过对核矩阵的计算和研究,从理论上对常用的核函数进行了评估.在此基础上,通过实验仿真证实了通过优选后的核函数所组成的混合核函数对支持向量机分类性能的改善,为核函数的选择提供了参考.     

基于射频技术的无线识别系统设计

本无线识别系统的设计利用射频技术,阅读器将呼叫信号加载到频率为70MHZ的射频上,以无线方式发给应答器。呼叫信号经过线圈耦合、解调、电压比较器等电路传送到应答器的控制器。控制器对呼叫信号进行分析、确认后,将存储的四位二进制编码通过发送端的调制电路馈送到阅读器,并显示应答器的具体信息。     

ANSYS在TBM步进支撑台座设计中的应用

采用TBM全断面隧道掘进机施工,步进支撑台座的可靠性和经济性是保证工程顺利进行的前提。结合罗宾斯TBM步进方案,选用合理可靠的步进支撑台座,应用ANSYS软件建立有限元模型,以求在保证TBM安全通过的前提下,确定出混凝土标号、浇注量及是否需要配筋等内容来解决施工经济性与便捷性问题。     

应用不等权重支持向量机预测人民币汇率的变动

基于金融时间序列的近期数据对未来的影响会大于早期数据,对应用于金融时间序列预测的支持向量机方法进行改进,给出了不等权重支持向量机方法（USVM）及其多项式光滑化处理。将不等权重支持向量机方法应用于训练样本集的子集确定预测模型,实证分析表明USVM算法预测是有效的。